What to do with an aggressive fish

We all make that mistake of seeing an extraordinary fish and instantly buying it at the fish store. Sometimes we know it may be risky and other times the fish just turns into a bully. So what can you do with an aggressive fish?

In a recent post, we shared a post titled “3 ways to avoid fish agression“, but what happens if they do start showing aggression? Hopefully these post will give you a few suggestions.

Occasionally fish may show aggression when a new fish is added to the tank. This is their way of showing they were there first and the new fish is not welcome. This is not as big as an issue as a continually aggressive fish.

You can try to catch the aggressive fish and hold it in a container until the new fish settles in or you can try rearranging your aquascape to shake up the territory the aggressive fish may be trying to protect. Unfortunately, removing the aggressor from the aquarium is a bit harder.

Having the aggressor contained keeps from stressing out the new fish.

If you are good at catching fish with a net and do not have much coral for the nets to get snagged on, you can try this method. This usually works best when you feed, it is near the surface, or when it’s sleeping.

You can also try a fish trap. These work by luring the fish in with bait and having a trap door where the fish can get in but not out. As you can imagine, you may need to try a couple of times before the right fish gets caught.

A big fish trap. The bigger the better as you don’t want it to look like a mouth.

If you know the fish likes to hide or sleep in a particular rock, you can remove the whole rock with the fish in it. Sometimes this works, sometimes it doesn’t.

Now you have the aggressive fish out of the aquarium, but what to do about it? If you have another aquarium, you might think about setting it up as a home for this fish. Otherwise, you’re left trying to sell or give away the fish.

If you are a member of a forum or a local fish club, try reaching out there to find a new home. If that doesn’t work, sometimes you are able to give it to a local fish store.

Depending on the fish in question, they might give you store credit or just take it off your hands. But before you trek down there with fish in hand, give the store a call to see if they actually will think it is a fish they could find a home for.

All of these methods may not work instantly but with persistence you will get the aggressive fish. First, start with the easy method of rearranging your aquascape and if that won’t work, look at remove the fish if necessary.